had returned from tortola with their daughter's body, the tyres demanded answers from their son-in-law. answers that weren't forthcoming. >> the first moment i heard it, i kept saying over the phone to him, but you had the buddy system. you were there. you had the buddy system. you were there. and he just kept saying i wasn't there. >> so they're saying you're the expert. you're the buddy. you're the caretaker of our daughter. >> they were wondering -- >> why'd you leave her. >> yeah. why did i let this happen. >> his first face to face meeting with them ended in a shoulding match. and for the next three years, there's suspicion of foul play. so much so that in 2002 her parents filed a wrongful death suit claiming swain was involved in shelley tyre's death. >> nothing that happens in the court takes care of our pain and our loss. >> i'm very, very emotional, yes. >> the tyres hired experts to investigate shelley's drowning. after traveling to tortola, they formulated this scenario which they reenacted on videotape. that david swain attacked her under water, approaching her from behind,